Creating Character Points is found on page 54 of GURPS Thaumatology as a variation of Devotional Enchantment.
Using the established rate of 8 hours = 1 energy and introducing 25 energy = 1 character point, it allows 200 hours (8x25) to buy a character point.
This is basically the first step (1 character point worth of Signature Gear buying 25 energy worth of enchantment) used in GURPS Fantasy to justify Meditative Magic in the first place.
The idea of 1 energy per 8 hours was based on reverse-engineering that.
The points are intended for use with T113's [[Magic Items as Advantages]] which would actually be creating an ALLY. Advantages on allies don't raise the value of the Ally advantage the same degree as a character getting those advantages themselves, so it is not as rapid an advancement as it might initially seem.
F131 also used a 1cp:1000energy ratio for high-enchantment campaigns (perhaps those where enchantment is plentiful due to Stable Magery or lots of mages) in which case it would take far more hours to buy a character point: 8000 (one thousand days).